Water filter assembly for use in an appliance

ABSTRACT

An apparatus for filtering water dispensed from an appliance (e.g., a refrigerator) includes a low-profile filter cartridge (or a bank of filter cartridges) releasably connected to a manifold assembly. The manifold assembly is in communication with the water inlet of the appliance and routs the filtered water to points of use. A water usage sensor in the manifold monitors the filter cartridge life and alerts the user when it is time to replace the filter. A latching mechanism includes a latching member 200 on the cartridge and a linearly moveable actuator 174 for releasably securing the filter cartridge to the manifold assembly. A flow control valve ensures that the water circuit remains closed when the filter cartridge is removed from the manifold.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of U.S. application Ser. No.10/210,890, filed Jul. 31, 2002, now allowed; and U.S. ProvisionalApplication No. 60/309,127, filed Jul. 31, 2001, the disclosure of whichis incorporated by reference.

FIELD OF THE INVENTION

The present invention relates generally to the field of residential andcommercial water filtration products. More specifically, the presentinvention relates to a replaceable water filtration assembly for use inwater dispensing appliances.

BACKGROUND OF THE INVENTION

Residential and commercial consumers have become increasingly concernedwith the quality of water they use every day. Whether their water comesfrom municipal sources or a well, these consumers increasingly rely onpoint-of-use filtration systems to insure that the water they consumehas the taste and appearance they desire. Because these systems continueto gain popularity, it has become increasingly important that systemmaintenance be quick and easy to accomplish.

An unfortunate drawback of point-of-use systems is that they must besmall enough to fit into the limited space available in the residentialand commercial markets. As overall size and a system's filteringcapacity are directly related, point-of-use systems require morefrequent filter media replacement than their industrial and municipalcounterparts. As many consumers will have little to no experience withwater filter systems, it would be desirable for a system to be capableof providing notice when maintenance is required and for thismaintenance to be performed quickly and easily.

SUMMARY OF THE INVENTION

The present invention addresses the disadvantages of the prior art byproviding a low profile modular filtering assembly for use in waterdispensing appliances. The method and apparatus for filtering waterdispensed by a water dispensing appliance comprises a low-profile filtercartridge releasably connected to a manifold assembly. The manifoldassembly is in communication with the wafer inlet to the appliance androuts the filtered water to points of use in the appliance. The manifoldassembly includes water usage sensor to monitor filter cartridge lifeand relay that information to the appliance, which will then alert theuser when it is necessary to replace the filter. A latching mechanism isincluded to releasably secure the filter cartridge to the manifoldassembly. A flow control valve ensures that the water circuit remainsclosed when the filter cartridge is removed from the manifold assembly.The cartridge and manifold assembly include registration features toensure that reverse installation of the cartridge will not occur.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a modular filter assembly according to anembodiment of the present invention;

FIG. 2 is an exploded view of a manifold assembly for a modular filterassembly according to an embodiment of the present invention;

FIG. 3 is a plan view of the manifold assembly with latch assembly ofFIG. 1;

FIG. 4 is an assembly drawing of the modular filter assembly accordingto an embodiment of the present invention;

FIG. 5 is a detail view of the modular filter assembly of FIG. 1;

FIG. 6 is a sectional plan view of the manifold assembly of a modularfilter assembly according to an embodiment of the present inventionshowing the flow diversion member in an open position;

FIG. 7 is a sectional plan view of the manifold assembly of a modularfilter assembly according to an embodiment of the present inventionshowing the flow diversion member in a closed position;

FIG. 8 is a water flow and control schematic for an intelligentappliance employing a modular water filter assembly according to anembodiment of the present invention;

FIG. 9 is an assembly diagram for a filter cartridge according to anembodiment of the present invention;

FIG. 10 is a front view of a filter cartridge according to an embodimentof the present invention;

FIG. 11 is a top plan view of a filter cartridge according to anembodiment of the present invention;

FIG. 12 is a rear view of a filter cartridge according to an embodimentof the present invention;

FIG. 13 is a side cross sectional view of a filter cartridge accordingto an embodiment of the present invention;

FIG. 14 is a perspective view of modular filter assembly according to anembodiment of the present invention;

FIG. 15 is a plan view of a modular filter assembly according to anembodiment of the present invention;

FIG. 16 is a side view of a modular filter assembly according to anembodiment of the present invention;

FIG. 17 is a perspective view of a modular filter assembly according toan embodiment of the present invention with one filter cartridgeunlatched;

FIG. 18 is the perspective view of FIG. 17 showing hidden detailaccording to an embodiment of the present invention;

FIG. 19 is the plan view of FIG. 15 showing hidden detail according toan embodiment of the present invention;

FIG. 20 is a the side view of FIG. 16 showing hidden detail according toan embodiment of the present invention;

FIG. 21 is a horizontal cross sectional view of a modular filterassembly according to an embodiment of the present invention;

FIG. 22 is a vertical cross sectional view of a modular filter assemblyaccording to an embodiment of the present invention;

FIG. 23 is a side view of a manifold assembly for a modular filterassembly according to an embodiment of the present invention;

FIG. 24 is a plan view of a manifold assembly for a modular filterassembly according to an embodiment of the present invention;

FIG. 25 is a front view of a manifold assembly for a modular filterassembly according to an embodiment of the present invention;

FIG. 26 is a perspective view of a manifold assembly for a modularfilter assembly according to an embodiment of the present invention;

FIG. 27 is a perspective view of a manifold assembly for a modularfilter assembly according to an embodiment of the present invention;

FIG. 28 is a side view of the manifold assembly depicted in FIG. 23showing hidden detail according to an embodiment of the presentinvention;

FIG. 29 is a plan view of the manifold assembly depicted in FIG. 24showing hidden detail according to an embodiment of the presentinvention;

FIG. 30 is a front view of the manifold assembly depicted in FIG. 25showing hidden detail according to an embodiment of the presentinvention;

FIG. 31 is an assembly drawing of a manifold assembly for a modularfilter assembly according to an embodiment of the present invention;

FIG. 32 is a perspective view of a modular filter assembly according toan embodiment of the present invention;

FIG. 33 is a top view of a modular filter assembly according to anembodiment of the present invention;

FIG. 34 is a plan view of a modular filter assembly according to anembodiment of the present invention;

FIG. 35 is a side view of a modular filter assembly according to anembodiment of the present invention;

FIG. 36 is a plan view of a filter cartridge blank according to anembodiment of the present invention;

FIG. 37 is a front view of the upper portion and lower portions of thefilter cartridge shell aligned for a joining operation according to anembodiment of the present invention;

FIG. 38 is a front view of a modular filter assembly according to anembodiment of the present invention;

FIG. 39 is a rear view of a modular filter assembly according to anembodiment of the present invention;

FIG. 40 is a front view of a manifold assembly for a modular filterassembly according to an embodiment of the present invention;

FIG. 41 is a cross sectional view of a filter cartridge according to anembodiment of the present invention; and

FIG. 42 is a cross sectional view of a filter cartridge according to anembodiment of the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

The filter assemblies 100 described herein may be used with a widevariety of appliances that use or dispense water, such as refrigerators,bottle-less water coolers and water filtration systems. The exemplarydescriptions of the preferred embodiment herein will be made withrespect to use in a refrigerator and are not intended to preclude theuse of the present invention in other appliances or applications.

Referring to FIG. 1, a modular water filter assembly 100 according to anembodiment of the present invention is shown. The filter assembly 100generally comprises a filter cartridge 102, a manifold assembly 104 anda latching assembly 106. The filter cartridge 102 may also receive anoptional end cap 108 in order to place written information visible tothe user and/or to enhance the visual appeal of the filter cartridge 102within an appliance.

Referring to FIG. 2, an exploded view of the manifold assembly 104 isshown according to an embodiment of the present invention. The manifoldassembly 104 generally comprises a manifold block 110, an inlet conduit112 and an outlet conduit 114. The inlet conduit 112 carries unfilteredwater to the manifold block 110 and the outlet conduit 114 carriesfiltered water away from the manifold block 110. The manifold assemblyincludes respective inlet 116 and outlet 118 receptacles for receivingthe conduits 112, 114. A male end 120 of each conduit 112, 114 isprovided with a sealing gasket 122, such as a rubber O-ring, and is theninserted into a respective receptacle portion 116, 118. A manifoldfastener 124 is then tightened onto the receptacles 116, 118 by threadedattachment or gluing. The conduits 112, 114 protrude through themanifold fastener 124, which cooperates with the enlarged male end 120of the conduits 112, 114 to maintain the fluid tight seal with themanifold block 110.

The manifold block 110 also defines a respective inlet port 126 andoutlet port 128 portions for receiving the filter cartridge 102. Eachport portion 126, 128 includes a groove or channel 130 therearound,which will be discussed further hereinbelow.

An internal fluid passageway 132 is defined within the manifold block110 for passing water therethrough. A portion of this fluid passagewayis referred to as the transverse channel 134. The transverse channel 134interconnects the inlet 136 and outlet 138 fluid passages. A flowdiversion device 140 is placed within the transverse channel 134 toselectively control the water flow in the manifold block 110. The flowdiversion device 140, also known as a spool valve, comprises anelongated member 142 having longitudinal surface 144 and a cam surface146 on a first end 148. Diverter seals 150, 152, 154 are disposed aboutthe longitudinal surface 144. Each of the diverter seals 150, 152, 154is annular in shape and defines a groove 156 therearound for receiving asealing gasket 158, such as a rubber 0-ring.

A biasing device 160, such as a spring, is placed in the transversechannel 134 in contact with a second end 162 of the flow diversiondevice 140. A cap 164 is fastened on an open end of the manifold block110 at the transverse channel 134. The first end 148 of the flowdiversion device protrudes slightly from the cap 164.

The manifold block 110 optionally includes a flowmeter housing portion166 in communication with the flow of filtered water arriving from thefilter cartridge 102. Those having skill in the art will also recognizethat the flow meter housing 166 may also be placed in communication withthe inlet flow of water without departing from the scope of the presentinvention. A flowmeter assembly 168 is disposable within the flowmeterhousing 166. The flowmeter assembly 168, according to a preferredembodiment, is an impeller wheel 170 that rotates in relation to thewater flowing through the outlet conduit 114. A cap 172 is used to sealthe impeller 170 within the flowmeter housing 166.

A hall effect sensor can be placed in proximity to the flow meterhousing 166 to sense the rotation of the impeller wheel 170. Theimpeller 170 contains a magnet that the hall effect sensor can use todetermine one or more of the number and speed of the revolutions of theimpeller wheel. The impeller shown in FIG. 2 is a radial flow design. Anaxial flow impeller wheel may be used alternatively within the scope ofthe present invention. An additional alternative embodiment may use anoptical sensor to count the revolutions of the impeller wheel.

An “intelligent” appliance can use the flow information from theflowmeter 168 to monitor the volume of water filtered by a givencartridge 102. The appliance can then indicate that the filter cartridge102 needs to be replaced based upon usage. Usage-based replacement isadvantageous over time-elapse replacement because a heavy water user maynot be receiving adequately filtered water by the time the filter isreplaced. Therefore, the heavy user may be exposed to contaminants thatwere thought to be filtered out. A light water user may replace a filterbefore its filtering properties degrade to the point of necessaryreplacement. This causes the light water user to needlessly spend moneyand generate waste.

Referring to FIG. 3, the latching assembly 106 is shown in cooperationwith the manifold assembly 104. The latching assembly 106 comprises alatch actuator 174, a bias member 176 and a latching collar 178. Thelatch actuator 174 is an elongated member having a push button 180 on afirst end 182 and a spring receiving feature 184 at a second end 186. Avalve actuator ramp 188 extends from the actuator's longitudinal surface190 adjacent the second end 186. A smaller cartridge release ramp 192 isformed adjacent to the valve ramp 188. The actuator 174 slides within aguide or guides (not shown) formed into or provided to the appliance toensure that the actuator 174 operates with a linear fore and aft motion.

A latch plate or collar 178 is provided to the grooves 130 in themanifold block 110. The collar 178, as shown in FIG. 4, is a generallyY-shaped member having an actuator protrusion 194 at the base and alatching aperture 196 defined in each of the branches. The void 198between the branches slidably engages grooves or channels 130 providedto the manifold block 110.

Referring to FIG. 4, the modular filter assembly 100 is assembled bysliding the latching collar 130 onto the manifold block 110, insertingthe cartridge 102 protrusions into their respective receptacles 116, 118in the manifold block and pushing the cartridge 102 into place until itcomes to rest at the point of full engagement. As the cartridge 102 isengaged with the manifold block 110, a latching member 200 engages alatching aperture 196 in the collar 130. Said engagement ensures thatthe cartridge 102 will not unintentionally unlatch during use. Theengagement of the cartridge 102 with the manifold assembly 104 resetsthe latching assembly 106, which moves the spool valve 140 into the openflow position. The fully latched filter cartridge 102 is shown in thedetailed view of FIG. 5.

When a user desires to remove the filter cartridge 102 for replacement,they push on the actuator 174. The movement of the actuator 174 causesthe cam end 146 of the diversion member 142 to ride up the valveactuator ramp 188, which urges the flow diversion device 140 to a closedposition, closing off the water flow to the filter cartridge 102. Thelatch release ramp 192 of the latch actuator 174 next contacts theactuator protrusion 194. This contact causes the collar 130 to movetransversely with respect to the movement of the latch actuator 174. Thetransverse movement of the collar 130 disengages the latching member 200of the filter cartridge. The user may then disengage the cartridge 102from the manifold block 110. Alternatively, a spring (not shown) may beused to eject the cartridge 102 from the manifold assembly 104 after thecartridge 102 has been unlatched.

Referring to FIGS. 6 and 7, the flow of water through the manifoldassembly 104 will be described. FIG. 6 illustrates a cross section ofthe manifold assembly 104 in the open position. Water enters from theinlet conduit 112, travels into the block 110 and enters the transverseconduit 134 between the first diverter seal 150 and the second diverterseal 152. The placement of the first 150 and second diverter seals 152allows the incoming fluid to pass through the inlet port 126 to thefilter cartridge 102. The first diverter 150 ensures that no watercontacts the spring 160, which is in the extended or relaxed state. Thesecond diverter 152 ensures that no incoming unfiltered watercommunicates with the outlet conduit 128.

A bleed port 149 is provided to a portion of the transverse channel 134adjacent the inlet port 126. The bleed port 149 communicates between thetransverse channel 134 and the exterior of the manifold block 110. FIGS.6 and 7 illustrate the function of the bleed port 149. The port 149 issealed from water flow by the position of the first diverter seal 150 inFIG. 6, corresponding to flow passing freely through the filtercartridge 102. When the spool valve 140 is in the closed position ofFIG. 7, the bleed port 149 allows water and air to escape from themanifold block 110. A drain conduit (not shown) may be provided to theoutlet of the bleed port 149 to capture water and air exiting the port149. In a relatively high-pressure system, the pressure in the cartridge102 remains under high pressure when the spool valve 140 is closed. Thebleed port 149 allows relief of this high pressure, thereby eliminatingthe potential of forceable disengagement of the cartridge 102.

Filtered water from the filter cartridge 102 enters the manifoldassembly through the outlet port 128, proceeds through the transversechannel 134, turns the flowmeter impeller 170 and exits through theoutlet conduit 114 on its way to a point of use. The filtered waterpasses between the second 152 and third 154 diverters before enteringthe flowmeter housing portion 166 of the manifold block 110. The seconddiverter 152 ensures that no filtered water mixes with unfiltered water.The third diverter 154 ensures that no water escapes from the manifoldblock 110 through the cap 164 on the transverse channel 134.

FIG. 7 illustrates the manifold assembly 104 in the closed-loopposition. The diversion device 140 is in the fully compressed position,which causes the second flow diverter 152 to prevent water from enteringthe inlet port 126. Instead, the unfiltered water flows along the member142 until reaching the third diverter 154. Once reaching the thirddiverter 154, the water must travel out through the outlet conduit 114because the outlet port 128 is blocked by the third diverter 154. Thisbypass system described herein allows water to flow to a point of usewithin the sealed circuit without leaking into the appliance even whenthe filter cartridge 102 is completely removed from the manifoldassembly 104.

Referring to FIG. 8, a representative control diagram for an intelligentrefrigerator is shown. Filtered water 201 flows from the outlet conduit114 of the filter assembly 100 towards several possible points of use.These points of use may be a user-selectable water outlet 202 and/or anice cube maker 204. Other point-of-use devices are contemplated by thescope of the present invention. A microprocessor 206 is electricallyconnected to the flowmeter 168 in the filter assembly 100 and to each ofthe point-of-use devices 202, 204. The microprocessor 206 senses thevolume of water filtered 201 with a sensor 205 that monitors therotation of the impeller 170 and correspondingly presents an indication208 to the user when to change the filter cartridge 102 based uponvolume of water used. The microprocessor 206 can also monitor the volumeof ice in the ice cube receptacle 204 with tray sensor 207, the statusof the user selectable water outlet 202, humidity sensors located atpoints in the refrigerator and leak detectors placed in the refrigeratorfor detecting water leaking from any source therein.

Referring to FIGS. 9-12, a filter cartridge 102 according to anembodiment of the present invention is shown. The filter cartridge 102generally comprises a shell 220, a filter element 222 and a filter cap224. The filter element 222 is disposed within the shell 220 and thenthe shell is sealed with the filter cap 224. The shell 220 is typicallyformed of plastic and manufactured by an injection molding operation.This is also the same process used to form the manifold assembly and thelatching assembly. The shell 220 defines a recess 226 therein forreceiving the filter element 222. The filter cap 224 includes twounitarily molded protrusions 228, 230; one corresponding to the inletport 228 and one corresponding to the outlet port 230. The cap 224 alsoincludes a resilient latching member 232 for securing the cartridge 102to the manifold block 110. This latching member 232 differs from thatdescribed in reference to FIGS. 1-5, and will be discussed in greaterdetail below.

Referring to the cross section side view of a filter cartridge 102 ofFIG. 13, the filter element 222 consumes less volume than the volume ofthe recess 226 formed in the shell. The purpose of this smaller volumeis apparent from an understanding of how such filtering cartridges work.The unfiltered water enters the cartridge through the water inletprotrusion 228. Then the water travels through the passage defined bythe gap 234 between the shell 220 and outside of the filter element 222.The filter element 222 defines its own internal passage 235 that is incontact with the filtered water outlet protrusion 230. Thus, all waterexiting from the filter cartridge 102 must pass through the filter media222. A plurality of spacers 236 and/or stiffening ribs may be placed atvarious points throughout the recess 226 in the shell 220 to maintainconsistent spacing and support for the filter element 222.

The filter element 222 is sealed within the shell 220 by a combinationof plastic welding techniques and glue. The filter cartridge 102 must behermetically sealed so that no water escapes therefrom and to ensurethan no external contaminants enter. The cap 224 includes an internallyprotruding portion 238 that contacts an edge 240 of the filter element222. This plastic-to-filter contact must be sealed with glue, such ashot melt glue or urethane, in order to provide a seal strong enough toprevent communication of the filtered and unfiltered water. Theshell-to-cap interface can be sealed by plastic welding techniques suchas vibration welding or ultrasonic welding. Alternatively, the cap 224can also be glued to the shell 220. The assembled filter cartridge 102is a low-profile design due to the rectangular prismatic filter element.

Referring to FIG. 37, an alternative embodiment for assembling thefilter cartridge 102 is shown. The shell 220 comprises an upper portion246 and a lower portion 248. The respective portions 246, 248 arejoinable along a perimeter interface by vibration welding, sonic weldingor glue. The cartridge 102 is assembled by placing the filter element222 into one of the upper 246 or lower 248 portions, placing thecorresponding portion thereon, aligning the interface and sealing. Thecap 224 is provided to the assembled shell in the same manner asdescribed above. Alternatively, the cap may be unitarily formed, inwhole or part, with the upper 246 and/or lower 248 portions.

The filter element 222 can be any suitable structure and composition forthe filtration of water. In some embodiments, the filter element 222comprises a polymer forming a porous matrix. Water passing through thefilter element passes through the pores to traverse the filter element.Example of suitable polymers include, for example, polyalkylenes,corresponding copolymers, substituted polyalkylenes and combinationsthereof. Suitable polyalkylenes include, for example, polyethylenes andpolypropylenes. Ultrahigh molecular weight polyethylenes for fibrilsupon the application of shear such that the fibrillated polymers canform desired pores. Filtration media for water formed from ultrahighmolecular weight polyethylene is described further in U.S. Pat. No.4,778,601 to Lopatin et al., entitled “Microporous Membranes OfUltrahigh Molecular Weight Polyethylene,” incorporated herein byreference.

In some embodiments, the filter media 222 includes fillers within thepolymer matrix, which can act as a binder for the filler particles. Forwater filtration, activated carbon particles can be a desirable filtersince the activated carbon can be effective to remove some compoundsfrom water. Activated carbon can also be referred to as charcoal. Insome embodiments, the filter element comprises from about 5 weightpercent activated carbon to about 95 weight percent activated carbon.Filters formed with ultrahigh molecular weight polyethylene (generallyfrom about 17 to about 30 weight percent) and activated carbon aredescribed further in U.S. Pat. No. 4,753,728 to VanderBilt et al.,entitled “Water Filter,” incorporated herein by reference. Water filterswith a majority by weight ultrahigh molecular weight polyethylene and aminority by weight activated carbon are available commercially fromPolymerics, Inc. (AKA, Polymerix Filters), Longmont, Colo.

The low profile cartridge 102 allows for greater packaging efficiencywhen used in appliances such as refrigerators. Refrigerators cannot havesubstantial space devoted to bulky filter cartridges because such spacedecreases the available space for storage or features. Simultaneously,however, the cartridge 102 must be effective and allow for placementwhere the user can easily access the filter cartridge 102.

Referring to FIGS. 14-22, a dual filter cartridge embodiment of thepresent invention is shown. This embodiment illustrates the concept thattwo or more filter cartridges 302, 304 may be linked together inoperable communication to filter an incoming water supply for multiplecontaminants. The multiple cartridge filter assembly 300 embodimentcomprises a first filter cartridge 302, a second filter cartridge 304and a manifold assembly 306.

The unfiltered water is introduced to the first cartridge 302 through aninlet conduit 308. The water filtered by the first filter cartridge 302exits an intermediate water outlet 310. The water exiting theintermediate water outlet 310 then passes through a flow connectorportion 312 of the manifold assembly 306 and introduces the water to thesecond filter cartridge 304. The second filter cartridge 304 filters theonce-filtered water and then passes the now twice-filtered water out toa point of use through an outlet conduit 314.

Referring to FIG. 17, a latching mechanism for securing the cartridgesto the manifold assembly is shown. The latching mechanism shown in FIG.17 is an alternative to that shown in FIGS. 1-5 and is ideally suitedfor low-pressure applications. The resilient latching member 232protrudes from the cartridge 304. A recess 316 is formed in a supportportion 318 of the manifold assembly 306 between the inlet 308 andoutlet 314 conduits. The latching member 232 includes an engagingsurface 242 and a sloped cam surface 244. A cartridge 302, 304 issecured to the manifold assembly 306 by aligning the respectiveprotrusions 228, 230 of the cartridge and the ports 126, 128 of themanifold. The cam surface 244 of the latching member 232 slides acrossthe support portion 318 as the protrusions 228, 230 are inserted intothe receiving ports 126, 128. The cartridge 304 is moved by the userinto further engagement until the cap 224 abuts against the ports 126,128. At the point of abutment, the engaging surface 242 of the latchingmember 232 engages the recess 316 in the support portion 318.

The resiliency of the latching member 232 causes the engagement surface242 to maintain this contact until the user exerts a removal forcesufficient to back the engagement surface 242 away from the recess 316.The engaging force exerted by the spring constant of the latching member232 is greater than the force created by the pressure of the watertrying to move through the inlet protrusion 228.

Referring to FIGS. 18-22, the flow control to the modular filterassembly 300 is controlled by the use of a poppet valve 320 placedin-line within the inlet portion 322 of the manifold assembly 306. Theuse of a poppet valve 320 simplifies the embodiment for the manifold 306utilizing a bypass system, as described previously. The use of thein-line valve 320 precludes the ability to permit water flow to pointsof usage when the filter cartridge 302, 304 is not in place. This isadvantageous in some instances because the passage of unfiltered waterdownstream of the manifold assembly 306 could contaminate the system toa degree that cleaning is needed before the water at the point of use isin acceptable condition.

FIGS. 23-31 show various illustrations and details of the manifoldassembly 306 according to am embodiment of the present invention. Inparticular, FIG. 31 illustrates the components and assembly of themanifold for a two-cartridge embodiment. The manifold assembly 306comprises a manifold block 324 having an inlet portion 326, an outletportion 328 and a connector portion 330 (previously the support portion318) therebetween.

The components of the poppet valve 320 are shown as provided to theinlet portion 326. It should be recognized that such a valve may also beprovided to each inlet portion 326 for a given cartridge to allow thatcartridge to be removed and to stop water flow without also having toremove the first cartridge 302. The poppet valve 320 comprises a poppet332, a spring 334, and a sealing gasket 336. The poppet 332 is urgedinto a sealing position against a valve seat 338 in the inlet portion322 by the spring 334.

The spring 334 then contacts a tubing retainer or cap 342. A washer 340and sealing gasket 344 are disposed within the retainer 342 to holdconduit 308, 314 firmly in place. Co-pending U.S. patent applicationSer. No. 10/210,776, entitled “TUBING ATTACHMENT,” filed Jul. 31, 2002and having the same inventive entity and assignee, further discloses thefeatures of the attachment device 342. Said Co-pending U.S. patemtapplication is hereby incorporated by reference herein.

The introduction of the inlet protrusion 228 of a filter cartridge 302,304 causes the poppet 332 to push against the spring 334, therebyproviding for fluid to flow into the inlet protrusion 228. The waterflows in through the inlet conduit 308, around the poppet 332, and intothe inlet 228 of the first cartridge 302.

Referring to FIGS. 21 and 31, a flow sensor 346 may be provided to themanifold assembly 306. An impeller 348 type flow sensor is disposedwithin the flow connector portion 312. An upper portion 350 of theconnector portion 312 of the manifold 324 is removable. A recess 352 forthe impeller is defined in the upper portion 350. The impeller 348 isrotationally mounted about a shaft 354 within the upper portion 350. Theupper portion 350 is then sealed to the lower portion 356 of theconnector portion 312.

Other types of flow control devices may be used instead of, or inaddition to, the two different embodiments described herein. A solenoidvalve may be placed in communication with the inlet conduit 308. Thesolenoid valve may be controlled by the microprocessor 206, whichdetermines if the filter cartridges 302, 304 are properly sealed inplace. The microprocessor 206 can also selectively turn the water flowoff if the filters 302, 304 are no longer working effectively and needto be replaced. This ensures that only properly treated water is allowedto pass downstream of the manifold assembly 306. A distribution valvemay also be used in place of the solenoid valve or the other valveembodiments described herein.

Referring to FIGS. 32-35, a modular filter assembly 400 comprising aseries of four filter cartridges 402, 404, 406, 408 is depicted as anembodiment of the present invention. The four cartridge embodimentcomprises a first filter cartridge 402, a second filter cartridge 404, athird filter cartridge 406, a fourth filter cartridge 408, a manifoldassembly 410, an inlet conduit 412 and an outlet conduit 414. Themanifold assembly 410 comprises an inlet portion 416, an outlet portion418, a first connector portion 420, a second connector portion 422 and athird connector portion 424. Each of the above portions 416, 418, 420,422, 424 is joined and supported by a support potion 426 betweenadjacent portions. A flowmeter 436 may be provided to one or more of theportions 420, 422,424.

Each of the four cartridges 402, 404, 406, 408 is arranged in a serieswherein the outlet of one cartridge supplies water to the inlet of anadjacent cartridge until the last cartridge 408 is reached. The lastcartridge 408 communicates with the outlet conduit 414, which suppliesfiltered water to points of use in the system. The present inventioncontemplates one or more filter cartridges and is not limited to onlyone, two or four as described herein. The present invention can bescaled up to more cartridges or scaled to fewer cartridges in order tosuit the needs of particular users.

Cartridge blanks 428 may be provided to a manifold 410 to allow afiltering system designed for multiple cartridges to be operated withless than the maximum number of cartridges. For example, an appliancedesigned to receive three filter cartridges for filtering threedifferent types of contaminants from water may not need all threefilters under certain circumstances. The filtering system cannot operatewith one of the filters removed because there is no path to communicatethe water to an adjacent cartridge or the outlet conduit. Therefore, afilter blank 428 may be used. The blank, as shown in FIG. 36, is asegment of plastic tubing 430 having an inlet side 432, an outlet side434 and a latching member 438. Each of the sides 432, 434 is configuredto communicate water between a given inlet portion and outlet portion ofa manifold assembly 410.

Referring to FIGS. 38-39, an alternative embodiment of the multiplecartridge layout is depicted. Each of the four filter cartridges 402,404, 406, 408 is stacked vertically, rather than side-by-side as inFIGS. 32-35.

A vertical manifold 440 for use with the vertical stack configuration isillustrated in FIG. 40. The manifold 440 comprises a plurality of inletportions 416 and outlet portions 418 corresponding to each of the first402, second 404, third 406 and fourth 408 filter cartridges. A firstconnector portion 420 operably connects the first 402 and second 404cartridges. A second connector portion 422 operably connects the second404 and third 406 cartridges. A third connector portion 424 operablyconnects the third 406 and fourth 408 filter cartridges. A flow meter436 may be provided to one or more of the connection portions 420, 422,424 for monitoring the volume of water flowing through the cartridges402, 404, 406, 408. Support structure 442 interconnects the variouscomponents of manifold 440 for support.

FIG. 40 illustrates the ability to provide a registration means for thecartridges within the manifold. The registration is accomplished bydiffering the size or shape of one of the inlet 416 or outlet 418portions of the manifold 440 and the corresponding inlet 228 or outlet230 protrusion of the cartridge 102. FIG. 40 illustrates a square-shapedinlet portion 444, a oversized inlet portion 446 and a square-shapedoutlet portion 448. It should be recognized that the size, shape andchoice of inlet/outlet size for the altered features is not limited tothe combinations or manifold configuration shown in FIG. 40. Anycircular, eccentric or polygonal shape that differs from itscorresponding inlet/outlet side is contemplated by the presentinvention. This method of providing registration ensures that the usercannot place a filter cartridge 102 into the manifold 440 backwards.

Referring to FIG. 41, an alternative embodiment of the filter cartridge102 is shown. A generally U-shaped or lung shaped filter element 252 isdisposed within the shell 220. A septum 254 divides the right half 256from the left half 258 of the element 252. The septum 254 provides addedstrength to the filter cartridge 102 for use in high-pressureapplications.

Referring to FIG. 42, another alternative embodiment of the filtercartridge 102 is shown. A first filter element 260 and a second filterelement 262 are disposed within the shell 220. A septum 254 divides theelements 260, 262 and ads strength to the cartridge 102, which may beneeded to maintain the integrity of the cartridge 102 in high-pressureapplications.

Although the present invention has been described with reference topreferred embodiments, workers skilled in the art will recognize changesmay be made in form and detail without departing from the spirit andscope of the invention.

1. A modular filter assembly comprising a filter cartridge comprising, ashell having an open end, a cap sealable on the open end of the shelland a generally rectangular filter element disposed within the shell,the cap having an inlet protrusion extending therefrom and an outletprotrusion extending therefrom; and a manifold assembly having an inletport for receiving the inlet protrusion and an outlet port for receivingthe outlet protrusion, one of the inlet protrusion and the outletprotrusion having a shape different than the corresponding inlet andoutlet protrusion to provide for registration of the filter cartridgewith respect to the manifold assembly.
 2. The modular filter assembly ofclaim 1, wherein the manifold assembly includes a flow meter housing forreceiving an impeller wheel, the flow meter housing in fluidiccommunication with the outlet protrusion of the filter cartridge.
 3. Themodular filter assembly of claim 2, wherein the flow meter housingfurther includes a sensor for sensing the rotations of the impeller, thesensor electrically connected to a microprocessor that monitors watervolume filtered by the filter cartridge.
 4. A method of filtering waterdispensed by a water dispensing appliance, the method comprising thesteps of: aligning an inlet protrusion of a filter cartridge with aninlet port of a manifold assembly in the appliance and aligning anoutlet protrusion of the filter cartridge with an outlet port of themanifold assembly; and urging the filter cartridge into the manifoldassembly, thereby actuating a flow control valve disposed within themanifold assembly to permit water to flow through the filter cartridgeand actuating a latching assembly to secure the filter cartridge to themanifold assembly.
 5. The method of claim 4, further comprising the stepof monitoring the volume of water being filtered by the filter cartridgeto determine the remaining service life of the filter cartridge.